RE: Rich data set
From: "Bachman, William" <bachmanw@globomax.com>
Subject: RE: Rich data set
Date: Wed, 23 May 2001 14:02:35 -0400
David,
You might try something like the following which allows all absorption related parameters (KA, ALAG1 & F1) to vary except the bioavailability of the reference formulation, which is fixed to one. Your data may sufficiently dense and informative to support all these parameters. It's worked for me for multiple formulations to allow assessment of relative F. Use FOCE with INTERACTION if possible.
Bill
William J. Bachman, Ph.D.
GloboMax LLC
7250 Parkway Dr., Suite 430
Hanover, MD 21076
Voice (410) 782-2212
FAX (410) 712-0737
bachmanw@globomax.com
$PK
TVCL=THETA(1)
TVV=THETA(2)
CL=TVCL*EXP(ETA(1))
V=TVV*EXP(ETA(2))
S2=V
;these 3 lines keep NONMEM from complaining about the if-then-elses
F1=1
KA=1
ALAG1=0
;reference formulation 1
IF (FORM.EQ.1) THEN
F1 =1.0
KA =THETA(3)*EXP(ETA(3))
ALAG1=THETA(4)+ETA(4) ;could also try expo iiv
ENDIF
;formulation 2
IF (FORM.EQ.2) THEN
F1 =THETA(5)*EXP(ETA(5))
KA =THETA(6)*EXP(ETA(6))
ALAG1=THETA(7)+ETA(8)
ENDIF
;formulation 3
IF (FORM.EQ.3) THEN
F1 =THETA(9)*EXP(ETA(9))
KA =THETA(10)*EXP(ETA(10))
ALAG1=THETA(11)+ETA(11)
ENDIF
;formulation 4
IF (FORM.EQ.4) THEN
F1 =THETA(12)*EXP(ETA(12))
KA =THETA(13)*EXP(ETA(13))
ALAG1=THETA(14)+ETA(14)
ENDIF